Since 1946, the San Diego Museum of Art has owned an appealing vision of happy prosperity: Frans Hals' 1630s painting of a plump, rosy-cheeked Dutch merchant whose expression and body language exude confidence, security and bonhomie.

In the early 1990s, on one of his infrequent visits to Los Angeles from Europe, Bernard Goodman asked his son, Simon, to take him to see it. Standing in front of the portrait of Isaac Abrahamsz Massa, Bernard for the first time permitted a crack in what his son calls "the brick wall of silence" that had confronted him and his older brother, Nick, all their lives.

Growing up in London after World War II, the Goodman brothers learned only after they were in their teens that their grandparents had been murdered by the Nazis and that their father was the dispossessed scion of one of the great banking families of Holland and Germany.

The Dutch estate of Friedrich "Fritz" Gutmann and Louise Gutmann von Landau had housed Old Master and Impressionist paintings — among them the Frans Hals portrait — as well as sculpture, Louis XV furniture, elegant Chinese porcelain and dazzling gold and silver clocks, vessels and tableware.

Bernard, his sons would learn much later, had limited success in recouping their grandparents' art after the war. He sold most of what he recovered to keep his now-struggling family going, sharing the proceeds with his sister, Lili.

As father and son stood in the museum gallery in San Diego, Simon Goodman recalled, "that painting started my dad talking a little. He started to open up — not too much, but he was just slightly emotional. It reinforced the concept that we'd lost everything."

Bernard Goodman died in 1994 in Germany, where, to his sons' great surprise, he'd settled after kindling a late-in-life romance with a German woman. She sent the contents of his desk to L.A., where Simon, now 66, has lived since transplanting the rock music importing and distribution business he'd owned from London in 1979. Nick, 68, is an art director for films and commercials who came to the U.S. in 1969.

Their father, who'd been studying at at Cambridge University before the war, then enlisted in the army, left correspondence, photographs and other records he had kept, finally giving the brothers a window on his search for missing art.

"Some families were so damaged that they didn't want to go back" where tragedy had overtaken them, Simon Goodman said. "My father was brave. He took the first boat to Holland after the war and started knocking on doors. Things dried up, eventually," but about 40 years later, Bernard's carefully kept records would contain enough clues for his sons to pick up the search.

For the most part, their father had recovered artworks initially rescued in France and Germany from 1944 to 1946 by art specialists attached to the U.S. Army — the units whose story inspired George Clooney's recently released film, "The Monuments Men."

"The problem, going back to the Monuments Men, is that nobody made any serious attempt to finish the job thoroughly," said Simon Goodman.

Under Allied policy, the military's art specialists — officially Monuments, Fine Arts and Archives units — sent their finds back to where they'd been before the war. It was left to each postwar government in Western Europe to restore the art to its owners or their heirs — if they were alive and could produce proof of who they were and what they'd owned.

Claimants faced daunting obstacles, including property laws that gave no special consideration to things the Nazis had stolen. In some nations, families that had been forced to sell art to Nazi agents for a pittance were out of luck because the legal codes said a sale was a sale, never mind the circumstances.

Jews had been the particular targets of art looting, and many of those who survived the war did not return to their former homelands. The Goodmans, who weren't religious, had in fact converted to Lutheranism in the 19th century, hoping it would help in the face of rising European anti-Semitism. The distinction was lost on the Nazis.

Some restitution experts say it was necessary for the Americans and British to trust the legal systems of nations not known for their goodwill toward Jews: "It would have been impossible, not just impractical, to do anything else" because of the costs and legal and logistical complexities of running a claims clearinghouse for all of Western Europe, said Thomas Kline, an art-restitution lawyer in Washington, D.C., who represented Nick and Simon Goodman in their first important recovery case.

Rose Valland, a French curator on whom Cate Blanchett's character in "The Monuments Men" is based, was Bernard Goodman's chief angel, to the extent he found any. She had spied on the Nazis as they hoarded looted Jewish art from across the Continent at the Jeu de Paume museum in Paris.

After the Allies reached Paris in 1944, she guided the Monuments Men in their searches. Simon and Nick Goodman saw from their father's records that Valland or her associate, Albert Henraux, personally had transferred three paintings to Bernard Goodman and his sister, who's now 94 and living in Italy.

Initially working from a list of their parents' major paintings they had compiled from memory, brother and sister also filed claims with the Dutch government. That bore some fruit, but Simon and Nick Goodman's later research showed that authorities held back about half of the Gutmann holdings the Monuments Men had sent to Holland.

Even the restitution Bernard Goodman received leaves a bad taste for Simon: He said the Dutch government insisted that his father pay off the mortgage and taxes on the family estate — debts accrued after 1943, when the Nazis arrested his grandparents, sent them to Theresienstadt and expropriated their home. Fritz Gutmann was beaten to death, after which his wife was transferred to Auschwitz and gassed.

Also dubious, Simon said, were exorbitant expense reimbursements his father had to pay to trustees a Dutch court had appointed to take charge of the family's holdings while he and his sister tried to prove that their parents were in fact dead, and they the legal heirs.

One of the works that passed from the Monuments Men to the Dutch to Bernard Goodman was "Still Life: Tea Set," a 1780s painting by the Swiss artist Jean-Etienne Liotard that now hangs in the J. Paul Getty Museum, which acquired it in 1984.

The Hals portrait that wound up in San Diego, and a Hieronymus Bosch painting, "The Temptation of St. Anthony," now at the National Gallery of Canada in Ottawa, may have been saved from looting — but nevertheless lost to the family — because Fritz Gutmann had sent them to be shown at an exhibition at the 1939 New York World's Fair.

A dealer who'd been a party to the loan arrangement sold the paintings without the family's knowledge or direct authorization after the war broke out, Simon Goodman said, but technically he'd been granted an "effective power of attorney," giving him a legal right to proceed. Bernard Goodman found the dealer after the war and received a payment.

"[My father] was very sad about the whole thing," Simon said, recalling the day in San Diego when he had opened up a bit.

As Nick and Simon Goodman took up the search — Nick as lead researcher in the early days, with Simon taking over in the early 2000s, when he sold his business and made the hunt his full-time job — they tapped resources unknown or inaccessible to their father.

The Monuments Men's records, now housed at a National Archives and Records Administration facility in Maryland, became a belated ace, dealt at last to the hand of justice. The Army art specialists had filled out a file card for each art object they'd found and had created transcripts of their interrogations of captured German officers and civilian art dealers who'd worked for the two most prominent Nazi art-lovers — Adolf Hitler and Hermann Goering. Hitler stockpiled looted art for a museum he wanted to establish in his hometown of Linz, Austria.

The art library at UCLA became another resource for the Goodman brothers, who paged through catalogs from exhibitions and art auctions, searching for references to Gutmann holdings. Simon says they soon began to benefit from the Getty Research Institute's enormous trove of original documents about art.

Their first success — a partial settlement, because of the legal complexities of the claim — was a small pastel landscape by Edgar Degas that a Chicago pharmaceuticals magnate had lent to the Art Institute of Chicago.

The case was grueling and expensive, settled by the businessman, Daniel Searle, in 1998 after a British documentary and CBS' "60 Minutes" had chronicled the brothers' underdog fight. When their money was running out, the Goodmans, media-savvy pros of the entertainment industry, applied pressure and rallied support by placing an appeal for help in a national Jewish publication, the Forward.

As time went on, they tried to do as much as possible themselves, saving the expense of lawyers and investigators. The Internet soon came into its own, and that, the brothers said, has made all the difference. From his cubbyhole office overlooking the swimming pool, brick patio and flowering trees in his Beverly Hills back yard, Simon can access the Nazis' own meticulous files, along with highlights of the Monuments Men archives and much more.

Photographs of brilliant silver and gold tea service vessels that the Goodman brothers tracked down at the Rijksmuseum, the Dutch national museum in Amsterdam, flank the computer on either side. Portraits of their great-grandparents look over Simon's shoulder.

Elsewhere in the house hang separate photographs of his grandparents, taken in 1926 by the American expatriate artist Man Ray. Fritz Gutmann, the very image of a resolute businessman, has the same dark eyebrows as Simon. Louise wears fur and a Garbo-esque mien of glamorous detachment.

Simon Goodman said he and his brother have identified about 400 works as former Gutmann holdings and so far have recovered more than half. About 240 varied pieces, including furnishings and porcelain figures, came in a 2002 settlement with the Dutch government. About 100 significant artworks and furnishings from the Gutmann collection remain at large, he said, and he aims to pursue vanished financial assets as well.

Because there are three primary heirs with three different households — Nick, Simon and their aunt, who needs money to support a disabled granddaughter — selling recovered art and dividing the proceeds usually makes more sense than keeping a piece. Also, Simon said, it's costly to continue the search, so it's important to have funds coming in.

Successes include a pair of fabulous gold clocks, made in Germany in the early 1600s, that the paper trail revealed had likely been stolen by a Nazi art dealer after they'd been found by U.S. Army troops but not immediately secured. The museum in Stuttgart, Germany, that had them on display paid to keep them — as did the Dutch Rijksmuseum, in the case of the three silver and gold decorative pieces pictured in Simon's office.

Simon's front hallway sports digital replicas of several of the most important recovered paintings. There's the Degas landscape that remains at the Art Institute of Chicago, a small portrait by Botticelli, and — an outlier because the Gutmanns' tastes were typically more conservative — "Sensuality," an 1890s painting by Franz Stuck of a sinister snake with bared fangs, coiled around a welcoming, voluptuously nude temptress.

"I found it about a mile and a half from where I live," Simon said — in the home of a man who'd received it decades earlier as a gift. Although the restitution required a year or so to present the proof and get a final response, he said the case ultimately came down to simple essentials.

"When I explained to him that it had belonged to a particularly brutal mass-murderer, and told him the story of what happened to my grandmother, it reduced this guy to tears," Simon said. "He said, 'I've heard enough, I don't like the painting any more.' He took it off his wall and helped me load it in my car."

The brothers said the world has improved for Holocaust art-restitution seekers since the mid-'90s, when they began.

By the end of 1998, an international conference on Holocaust art had met in Washington, D.C., adopting a set of nonbinding principles in which governments — but not individual collectors or non-governmental museums — pledged to consider claims fairly instead of giving them the brush-off or concealing suspect works. More recently, some art museums have begun proactive measures, checking ownership histories of their holdings for red flags associated with art that changed hands during the Nazi era, and for potentially looted antiquities.

Institutions such as the Getty and the Norton Simon Museum still fight claims they consider flawed. But less rare, now, are instances such as an announcement made by Rutgers University three years ago that, without a lawsuit having been filed, it was returning a 1509 portrait by Hans Baldung Grien to the Goodmans. An art dealer had given the German painting to Rutgers' Zimmerli Art Museum in 1959.

"We are enormously proud to be able to make this right," a university official said on its return to the brothers.

Besides continuing the hunt for stolen art, Simon Goodman is busy writing the final chapters of a book, tentatively called "Blood and Treasure," that tells the story of what his family lost and what it has found.

"It's not about the money," he said. "It's about the satisfaction of the justice I've brought about. I was always tortured by how tortured my father was, the silence where we couldn't talk. Now I have this feeling that my dad and my granddad are smiling down on me."

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